In article 91-08-043 canver@cyborg.informatik.uni-ulm.de (Ercument Canver) writes:>I got the following problem: I need to extend the parse tables generated>by yacc dynamically during parsing a text. ...>>Background: I'm posting this request because I have to write a parser suitable>for declaring mixfix operators and overloading.>>I'd also appreciate pointers to parser generaters dealing with this kinda>problem (not necessarily yacc-like).

You may want to attack the problem with lex instead of yacc. Read:
PARSING DISTFIX OPERATORS by Edgar H. Sibley in Commmunications of the ACM
February 1986, Vol 29, num 2, page 118.
Abstract:
The advantages of user-defined distfix operators -- a syntactic
convenience that enhances the readability of programs -- can be
obtained as an extension of almost any programming language without
requiring dynamic changes to the parser.
Conclusions:
We have described a simple technique whereby a fixed BNF grammar can
describe languages including user-defined infix, postfix, and distfix
operators. The technique requires only that the parts of disfix
operators be lexically distinguishable. ...
The idea has been successfully implemented [with YACC] with minimal
effort.

Note that "lexically distinguishable" means that lex can look up the
answer in a table, which can grow dynamically. I'm not sure how Sibley's
ideas interact with overloading.